package com.hansming.bss.common.utils;

import java.awt.image.BufferedImage;
import java.awt.Color;  
import java.awt.Font;  
import java.awt.Graphics;   
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
* 封装生成图片验证码的工具类.
* 1.Commons-Codec的 hex/base64 编码
* @author hansming
* @version 2017-09-15
*/

public class ValidateCodeUtil {
	
	private Logger logger = LoggerFactory.getLogger(getClass());

	 public static final String RANDOMCODEKEY= "RANDOMVALIDATECODEKEY";//放到session中的key     
	    //private String randString = "0123456789";//随机产生只有数字的字符串 private String
	    //private String randString = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";//随机产生只有字母的字符串
	    private String randString = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";//随机产生数字与字母组合的字符串  
	    private int width = 130;// 图片宽  
	    private int height = 40;// 图片高  
	    private int lineSize = 40;// 干扰线数量  
	    private int stringNum = 4;// 随机产生字符数量  
	    
	    private Random random = new Random();
	 
	    /*
	     * 获得字体
	     */
	    private Font getFont() {
	        return new Font("Fixedsys", Font.CENTER_BASELINE, 18);
	    }
	 
	    /*
	     * 获得颜色
	     */
	    private Color getRandColor(int fc, int bc) {
	        if (fc > 255)
	            fc = 255;
	        if (bc > 255)
	            bc = 255;
	        int r = fc + random.nextInt(bc - fc - 16);
	        int g = fc + random.nextInt(bc - fc - 14);
	        int b = fc + random.nextInt(bc - fc - 18);
	        return new Color(r, g, b);
	    }
	 
	    /**
	     * 生成随机图片
	     */
	    public void getRandcode(HttpServletRequest request,
	            HttpServletResponse response) {
	        HttpSession session = request.getSession();
	        // BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类  
	        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
	        Graphics g = image.getGraphics();// 产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操作  
	        g.fillRect(0, 0, width, height);
	        g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));
	        g.setColor(getRandColor(110, 133));
	        // 绘制干扰线  
	        for (int i = 0; i <= lineSize; i++) {
	            drowLine(g);
	        }
	        // 绘制随机字符  
	        String randomString = "";
	        for (int i = 1; i <= stringNum; i++) {
	            randomString = drowString(g, randomString, i);
	        }
	        //将生成的随机字符串保存到session中，而jsp界面通过session.getAttribute("RANDOMCODEKEY")，  
	        //获得生成的验证码，然后跟用户输入的进行比较  
	        session.removeAttribute(RANDOMCODEKEY);
	        session.setAttribute(RANDOMCODEKEY, randomString);
	        g.dispose();
	        try {
	            // 将内存中的图片通过流动形式输出到客户端  
	            ImageIO.write(image, "JPEG", response.getOutputStream());
	        } catch (Exception e) {
	            e.printStackTrace();
	        }
	 
	    }
	 
	    /*
	     * 绘制字符串
	     */
	    private String drowString(Graphics g, String randomString, int i) {
	        g.setFont(getFont());
	        g.setColor(new Color(random.nextInt(101), random.nextInt(111), random
	                .nextInt(121)));
	        String rand = String.valueOf(getRandomString(random.nextInt(randString
	                .length())));
	        randomString += rand;
	        g.translate(random.nextInt(3), random.nextInt(3));
	        g.drawString(rand, 13 * i, 16);
	        return randomString;
	    }
	 
	    /*
	     * 绘制干扰线
	     */
	    private void drowLine(Graphics g) {
	        int x = random.nextInt(width);
	        int y = random.nextInt(height);
	        int xl = random.nextInt(13);
	        int yl = random.nextInt(15);
	        g.drawLine(x, y, x + xl, y + yl);
	    }
	 
	    /*
	     * 获取随机的字符
	     */
	    public String getRandomString(int num) {
	        return String.valueOf(randString.charAt(num));
	    } 	
}
